144346-05-4Relevant articles and documents
Electrophilic cleavage of rhenium-oxygen bonds by Br?nsted and Lewis acids
Simpson, Robert D.,Bergman, Robert G.
, p. 3980 - 3993 (2008/10/08)
The rhenium-oxygen bond in complexes of the type (CO)3(L)2ReOR (1 (R = CH3) or 2 (R = CH2CH3)) may be cleaved by a number of Br?nsted and Lewis acids. When an acid X-H is added to 1 or 2, one observes the formation of the exchanged rhenium product (CO)3(L)2ReX and the free alcohol (L = 1,2-bis(dimethylarsino)benzene (diars, a), 1,2-bis(diethylphosphino)ethane (depe, b), PME3 (c), (2S,4S)-2,4-bis(diphenylphosphino)pentane (bdpp, d), or 1,2-bis(diphenylphosphino)ethane (dppe, e)). For the reactions with Br?nsted acids, the reaction is reversible when aniline and certain other amines are added to 1 or 2, but the reaction may be driven to the right by the removal of the alcohol from the reaction mixture. Using this technique, the arylamido complex (CO)3(depe)ReNHC6H5 (13b) has been synthesized and its structure determined by a single-crystal X-ray diffraction study. Irreversible exchange occurs upon reaction with other acids such as R2PH, RPH2, H2S and CpW(CO)3H. The terminal phospido complexes are fluxional in solution, undergoing phosphorus inversion at temperatures much lower than the free phosphines. The alkoxides do not react cleanly with carbon acids, but the alkoxide ligands may be removed using alkyl-and alkenylboranes, leading to alkenylrhenium complexes.